Acoustic instrument



Feb. 9, 1932. LINSELL 1,844,014

AcOUsc NsTRUMENT INVENTOR ALFRED A. UNsELL oRNEY Patentea Fb. -9, 1932 UN TED SATES PATENT oFoE 11 lieatin 1ed .T111 13, 1928, SeTiaI 1 292,444, End in GTeat Britain u nst 30, 1927.

ThiS invention reloteS to 8ooustic instr11- InentS, afld iS )a rtio111arly o Plicable to loud S eokers gra11o honeS ond the like.

1t iS Well known that in Inany aoouStio in l StfI1IIle11tS, 1T1ofe eSPeCil1y thoSe haviIlg di9-- 1)11 agn1S of large ofea, Slloh os afe eIn loyed in Socl1ed hornless 10Lld SpeokerS, interfefenCe iS a ot to ocour betvveen the Sound vvaveS en1itted froIn the front of the diaphTagIn and 10 thoSe enoitted from the baok.

One fvay of II1iI1iII1izing of avoiding Soch inteffeTence iS to rovide 3 b1e 1te, independent of the diaphragIn, and to n1Ount it iI1 Sllch o oSition vvith feS eCt to the Soid 5 diaphfagln that SoIInd T oveS are SubStan til1y pfevented froIn paSSing froln ffont fo feor thefeof of vice verS3.

11ccofding to thiS invention the diaphragIn of an couStio inStrnInent iS itSelf so foTIned 2o and arfanged aS to act aS a baf11e aS WeH aS to eInit soUnd, vvhereby the roviSion of o SeParate baff1e Plate of 1rge Size iS fendefed unneoeSSary.

The invention iS illuStrated in the aooon1 83 panying dfowingS in Which= iguro 1 ShovS 8 Side vievv of an inStTL1 Inent ConStrncted in accordance vvith Iny in vention,

igure 2 ShovvS on end vievv of the inStru So ment of Eig. 1,

1 igoreS 3 to 11 iTlc111Sive shovv Inodifioat-ionS of the 1nStTuInent of `ig11I'e 1.

1efefring to the oonStruction Shovvn in Side vieW in 1figllfe 1 nd en(1 vievv in 1figtlre 2, n

of coInPriSes 3 Cone Shaped dioPhrgIn 1 hav ing a fTee edge an(1 oda ted to be iInpulSed in knovvn InanneI' by nleonS of coil 2 to vv11ich CUrfentS of ooouStic ffeqenoy afe fed 0 nd vvhich iS vVound u on a ring 3 and i1n InerSed in the annulaT air gap of a Inagnet sySteIn (not shovvn). 111e TiIn of the di1 phrogn1 1 iS Seoured to the inneI oI1Tved Side of on open-ended oylinder 1, halfvvay along' 5 itS length. The cylindeT 1ies vvith its axis SL1bStoI1fil1y in the Sa111e Sffoig11t line aS the oxiS of the Cone, and iS of 1eaSt aS long aS one eighth of t11e longeSt vva ve length the inStru111ent iS C1eSifeC1 to re )Toduoe, So that a ColTl )TeSSiona1 vve, Staftig ffon1 the edge of fho Conioal oftioH of the dioPhfgn1 adI1(1 tfavelling firSt in fhe SaIne (1ireCtion to one edge of the cylindficol poftion, then back to the oppoSito edge theTeof, nd then back again line on the oufved SurfoCe of the Said oy1in driCal portion 1 aS Shov 1, of So oS to ioin tho edge of the oone 1 to that edge of the cylin` driCa1 Portion 1 nereSt the ape of t11e Sid coI1e.

7 In anothef InodiCfion, i11LlStrated in ig- 11I'e 5, the lTlain Sound eInitting oftion 1 of the d hTagmi. e. that poftion fo Which the oylindTioa1 )ortion iS attchediS Hafed of the InotIth. In thiS ofrongeInent, foI' ex an1ple, the melnbef 1 iS So ShopoC1 that the 1)rt vl1ich 1ioS vithin the oylindfiCl poftion ap earS in section aS tTvo $ubStonfiolly cif cLllaf aJrcS 1, 1o, Sobtending a foxi111atoly each 90 and strnok eCh vith a rodills eqool to ha1f the length of tho cylinder, So fhot the tvvo Said afcs Lfe nofInol to the Surfaoe of the Sid oy1i11de of the oint of iI1T1ctnre.

In fIlrt11er 1T10(1ifioation the conical portion 1 of the diaphragIn vhioh Inoy be flafed of tho n1outh if deSifed, iS Secured to the oylindTicol )ortioI1 t one of other of the oiroulof In t11iS caSe the annulus- GERTIFIGATE OE GORREGTION- Patent No. 1,844,014. Eebruary 9, 1932.

ALERED AUBYN LINSELLl lt S heTeby certified that error appears in the printed Specificaton of the abovo numbered patent requiring correction aS foovS= Page Z, ne 37, for the Word "Simnar" fead smaller; and tha the Sa Letters Patont should bo road With iS correction theTein that ho same may conform to the rooord of the oaSe in the Patent office.

Signed and sealed thS lZth day of July, A. D. 1932.

M. J. Moore, Acng GommisSioner of Patents.

Seal GERTIFIGATE OE coBREGTION,

Patent No. 1,844, 014. Eebruary 9, 1932.

ALERED AUBYN LINSELL- I s hereby certfied that orror appearS in the printed spocification of the above nomberod patent requiring correction as folovs= Page Z, ne 37, for the Word SimHar" read smaer; and hat the said Letters Patent should be road Wh thiS corroction therein that the same mayoonform to the record of the oase in the Patont offioe,

Signed and Sealed this lZth doy of .Iuly, A, D. 1932.

M. J. Mooro, (Seal) Aotng Gommissioner of Patents. 

